Battery cover and battery

Abstract

The present invention belongs to the field of battery technology, and discloses a battery cover and a battery, wherein the battery cover comprises a cover body provided with an injection hole, the cover body comprising a first surface, a second surface, an injection structure and an anti-top groove, the injection structure forms a sink on the first surface and a convex on the second surface, the injection hole is located in the sink, the anti-top groove is provided on the second surface, and is arranged around the outer side of the convex, the width dimension of the anti-top groove is W, and satisfies 0.8mm≤W≤1.2mm. When punching a hole in the sink, a specific tool is inserted into the anti-top groove to obtain a larger supporting force opposite to the force applied during punching, thereby preventing the sink from collapsing during punching, ensuring the horizontality of the sink and the verticality of the inner wall of the injection hole after forming, so that the sealing nail fits tightly against the sink surface and the inner wall of the injection hole, has good sealing performance, increases the contact area, increases resistance, and improves the connection stability and firmness after assembly.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery cover and a battery. Background Art

[0002] As a crucial component of lithium-ion batteries, the battery cover's structural design not only impacts basic battery performance, such as capacity and charge / discharge efficiency, but also directly impacts safety and long-term reliability. The battery cover's primary components include conductive posts, a bare aluminum plate, insulators, and explosion-proof valves. The insulators, typically made of plastic, insulate the conductive posts to prevent short circuits caused by contact between the insulators and the bare aluminum plate. The explosion-proof valves are designed to prevent thermal runaway from occurring, allowing high-temperature, high-pressure gases within the battery to break through the valves, thereby providing pressure relief.

[0003] The battery cover is also provided with an injection hole for injecting electrolyte into the battery. After the injection operation is completed, a sealing nail is inserted into the injection hole to seal the injection hole and prevent the electrolyte from leaking from the injection hole.

[0004] However, the injection holes on the battery cover are usually made by punching technology at present, and a sink is formed on one side of the battery cover and a convex is formed on the other side of the battery cover. However, the battery cover of this structure will be subjected to a large concentrated force when punching. Under the impact of the large concentrated force, the sink surface will collapse radially toward the center axis of the injection hole, which will lead to poor horizontality of the sink surface on the one hand, and poor verticality of the inner wall of the injection hole after forming on the other hand. As a result, after the sealing nail is inserted, the sealing nail cannot fit tightly with the sink surface and the inner wall of the injection hole, resulting in poor sealing and easy leakage of electrolyte. Moreover, after entering the high-temperature standing and formation processes, the sealing nail with a small contact area with the injection hole will be easily affected by the gas production inside the battery, resulting in the problem of falling off due to small resistance, and the connection stability and firmness are poor. Summary of the Invention

[0005] The object of the present invention is to provide a battery cover and a battery with good sealing performance, high connection stability and firmness.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] In one aspect, a battery cover is provided, comprising a cover body having a liquid injection hole, the cover body comprising a first surface, a second surface, a liquid injection structure, and an inverted top groove, the liquid injection structure being recessed from the first surface toward the second surface, and being configured to simultaneously form a sunken platform on the first surface and a convex platform protruding from the second surface, the liquid injection hole being located within the sunken platform, and the inverted top groove being provided on the second surface and surrounding the outer side of the convex platform;

[0008] The width of the reverse top groove along the first direction is W, and satisfies 0.8 mm ≤ W ≤ 1.2 mm.

[0009] Optionally, a depth dimension of the anti-top groove along the second direction is t1, and satisfies 0.2 mm ≤ t1 ≤ 0.4 mm.

[0010] Optionally, the thickness dimension of the cover plate body is t2, and satisfies 0.1≤t1 / t2≤0.2.

[0011] Optionally, a height dimension of the boss protruding from the second surface along the second direction is t3, and satisfies 0.35≤t3 / t2≤0.6.

[0012] Optionally, a height dimension t3 of the boss protruding from the second surface along the second direction satisfies 0.7 mm ≤ t3 ≤ 1.2 mm.

[0013] Optionally, the depth dimension of the sink is t4, and satisfies (t2-t1-t4)≥0.3mm.

[0014] Optionally, a projection area of the inverted top groove on the sinking platform along the second direction has a width dimension L along the first direction, and satisfies L / W≥0.6.

[0015] Optionally, the injection hole includes a fixed hole section and a guide hole section, the guide hole section is located on the side of the injection hole close to the first surface, and the fixed hole section is located on the side of the injection hole close to the second surface. The guide hole section is a trumpet-shaped section with an inner diameter gradually increasing as it moves away from the fixed hole section, and the inner wall of the fixed hole section is perpendicular to the first surface.

[0016] Optionally, the boss is in a conical shape with an outer diameter gradually decreasing in a direction approaching the pole group.

[0017] On the other hand, a battery is provided, comprising a battery casing, an electrode group and a battery cover as described in any one of the above items, wherein the battery casing is a hollow shell structure with an opening, and the battery cover is arranged on the opening of the battery casing and closes the battery casing to form a accommodating cavity for accommodating the electrode group.

[0018] Beneficial effects of the present invention:

[0019] The present invention provides a battery cover, which is provided with a reverse top groove surrounding the outer side of the boss on the second surface of the cover body, and is inserted into the reverse top groove by using a specific tool, so that when the injection hole is formed in the sinking platform by using a punching process, a supporting force opposite to the force during punching is provided to the cover body, and the width dimension W of the reverse top groove along the first direction is limited to obtain sufficient supporting force to prevent the sinking platform from collapsing during punching, ensure the horizontality of the sinking platform and the verticality of the inner wall of the injection hole after forming, so that after the sealing nail is inserted into the injection hole, it can fit tightly with the sinking platform surface and the inner wall of the injection hole, has good sealing performance, and increases the contact area and increases the resistance, thereby improving the connection stability and firmness of the cover body and the sealing nail after assembly.

[0020] The present invention also provides a battery, which, by applying the above-mentioned battery cover, improves the sealing performance, reduces the probability of electrolyte leakage, and improves product quality. On the other hand, it avoids the problem of sealing nails falling off during manufacturing, thereby improving the manufacturing yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a partial structural diagram of the battery cover provided by the present invention;

[0022] Figure 2 yes Figure 1 Enlarged cross-sectional view of part I;

[0023] Figure 3 It is a partial structural schematic diagram of the battery provided by the present invention.

[0024] In the picture:

[0025] 100. Battery housing; 200. Electrode group;

[0026] 1. Cover plate body; 11. Liquid injection hole; 111. Fixing hole section; 112. Guide hole section; 12. First surface; 13. Second surface; 14. Liquid injection structure; 141. Sink; 142. Boss; 15. Anti-top groove. DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0028] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0029] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0030] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meanings.

[0031] Because the battery cover is subjected to a large concentrated force when the injection hole is made by the punching process, the sunken table formed on the battery cover collapses radially toward the central axis of the injection hole, resulting in poor horizontality of the sunken table and the verticality of the inner wall of the injection hole after forming. As a result, the sealing nail inserted into the injection hole cannot fit tightly with the sunken table and the inner wall of the injection hole, resulting in poor sealing and connection stability.

[0032] Therefore, in order to improve the horizontality of the countersunk surface during punching and the verticality of the inner wall of the injection hole after forming, the sealing pin inserted into the injection hole is tightly fitted with the countersunk surface and the inner wall of the injection hole, thereby improving the sealing and connection stability, this embodiment provides a battery cover, which includes a cover body and a sealing pin. The cover body is provided with an injection hole for injecting electrolyte, and the sealing pin is inserted into the injection hole.

[0033] like Figures 1 to 3As shown, the cover body 1 includes a first surface 12, a second surface 13, an injection structure 14 and an anti-top groove 15. The injection structure 14 is recessed from the first surface 12 to the second surface 13 to form a sink 141 on the first surface 12 and a boss 142 protruding from the second surface 13 on the second surface 13. The injection hole 11 is located in the sink 141. The anti-top groove 15 is provided on the second surface 13 and is arranged in a ring around the outer side of the boss 142. The width dimension of the anti-top groove 15 along the first direction is W, and satisfies 0.8mm≤W≤1.2mm.

[0034] By opening a counter-top groove 15 surrounding the outside of the boss 142 on the second surface 13 of the cover body 1, a specific tool is inserted into the counter-top groove 15, so that when the injection hole 11 is formed in the sink 141 by the punching process, a supporting force opposite to the force during punching is provided to the cover body 1, and the width dimension W of the counter-top groove 15 along the first direction is limited to obtain sufficient supporting force to prevent the sink 141 from collapsing during punching, to ensure the horizontality of the sink 141 and the verticality of the inner wall of the injection hole 11 after forming, so that after the sealing nail is inserted into the injection hole 11, it can fit tightly with the sink surface and the inner wall of the injection hole 11, has good sealing, and increases the contact area and increases the resistance, thereby improving the connection stability and firmness after the cover body 1 and the sealing nail are assembled.

[0035] Among them, the battery cover can be used in many different types of batteries, such as blade batteries, square shell batteries or large cylindrical batteries, etc. In this embodiment, the battery cover is used in square shell batteries, and even if they are all square shell batteries, there are many types of battery covers, so the layouts of different types of battery covers are also different. Therefore, the formation positions of the boss 142 and the sinker 141 formed on the cover body 1 can be freely adjusted according to actual needs. Since the boss 142 is a structure formed by stamping the sinker 141, the shape of the cross section of the boss 142 is the same as the shape of the cross section of the sinker 141, and the cross sections of the two can be circular, elliptical or polygonal, etc. In this embodiment, the cross-sectional shapes of both the boss 142 and the sinker 141 are circular, wherein the hole type of the injection hole 11 should be adapted to the cross-sectional shape of the sinker 141. In this embodiment, since the cross-sectional shape of the sinker 141 is circular, the injection hole 11 is a circular through hole.

[0036] Alternatively, as Figure 1 、 Figure 2As shown, the depth dimension t1 of the reverse top groove 15 along the second direction satisfies 0.2mm≤t1≤0.4mm. By limiting the depth dimension t1 of the reverse top groove 15 along the second direction to 0.2mm≤t1≤0.4mm, the reverse top groove 15 is prevented from being too shallow, which would make it difficult to engage and secure with the tooling when mated. Furthermore, the reverse top groove 15 is prevented from being too deep, which would reduce the structural strength of the cover body 1 and result in poor pressure bearing capacity of the cover body 1.

[0037] In this embodiment, the depth dimension t1 of the reverse top groove 15 along the second direction can be any value between 0.2 mm and 0.4 mm or a range between any two values, such as 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, etc.

[0038] Alternatively, as Figure 1 、 Figure 2 As shown, the thickness dimension of the cover plate body 1 is t2, and satisfies 0.1≤t1 / t2≤0.2. By limiting the ratio between the depth dimension t1 of the reverse top groove 15 along the second direction and the thickness dimension t2 of the cover plate body 1 to satisfy 0.1≤t1 / t2≤0.2, the thickness dimension t2 of the cover plate body 1 can be determined based on the depth dimension t1 of the reverse top groove 15 along the second direction. On the one hand, this avoids the cover plate body 1 being too thin, resulting in weak structural strength, and on the other hand, it avoids the cover plate body 1 being too thick, resulting in an increase in overall structural size and increased manufacturing cost.

[0039] Among them, in order to verify the influence of the setting of the relevant structural dimensions of the anti-top groove 15 of the cover body 1 on the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 after molding, the depth dimension t1 of the anti-top groove 15 along the second direction, the thickness dimension t2 of the cover body 1 and the width dimension W of the anti-top groove 15 along the first direction are set, and a batch of products are prepared according to the set dimensions. If the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is less than 0.01%, it is the optimal structure, and the batch of products meets the design requirements. As shown in Table 1, for the different size settings of the depth dimension t1 of the anti-top groove 15 along the second direction, the thickness dimension t2 of the cover body 1 and the width dimension W of the anti-top groove 15 along the first direction, eight groups of embodiments and nine groups of comparative examples are designed, and a total of seventeen batches of products are tested and verified, wherein the number and product specifications of each batch are the same.

[0040] Table 1

[0041]

[0042] In Example 1, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.25 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.125. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 0.8 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0071%.

[0043] In Example 2, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.25 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.125. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 0.85 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0067%.

[0044] In Example 3, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.25 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.125. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 0.9 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0051%.

[0045] In Example 4, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.25 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.125. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 1 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0055%.

[0046] In Example 5, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.25 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.125. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 1.1 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0062%.

[0047] In Example 6, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.25 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.125. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 1.2 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0069%.

[0048] In Example 7, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.3 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.15. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 0.85 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0069%.

[0049] In Example 8, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.4 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.2. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 0.85 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0072%.

[0050] It can be seen from Examples 1 to 8 that when the depth dimension t1 of the anti-top groove 15 along the second direction satisfies the range of 0.2mm≤t1≤0.4mm, the ratio between the depth dimension t1 of the anti-top groove 15 along the second direction and the thickness dimension t2 of the cover body 1 satisfies the range of 0.1≤t1 / t2≤0.2, and the width dimension W of the anti-top groove 15 along the first direction satisfies the range of 0.8mm≤W≤1.2mm, the defective ratios of the horizontality of the sink 141 with the liquid injection hole 11 and the verticality of the inner wall of the liquid injection hole 11 of this batch of products are both less than 0.01%, which meet the optimal design requirements.

[0051] In comparative example 1, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 0 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 1.53%.

[0052] In comparative example 2, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0 mm, and then the thickness dimension t2 of the cover body 1 is set to 4 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 0 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 1.27%.

[0053] It can be seen from Comparative Examples 1 and 2 that for this batch of products without the anti-top groove 15 on the cover body 1, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 is far greater than 0.01%.

[0054] In comparative example 3, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.15 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.075. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 0.85 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0186%.

[0055] In comparative example 4, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.18 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.09. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 0.85 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0167%.

[0056] In comparative example 5, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.45 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.225. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 0.85 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0179%.

[0057] In Comparative Example 6, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.5 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.25. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 0.85 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0147%.

[0058] It can be seen from Comparative Examples 3 to 6 that when the depth dimension t1 of the anti-top groove 15 along the second direction does not satisfy the range of 0.2mm≤t1≤0.4mm, and the ratio between the depth dimension t1 of the anti-top groove 15 along the second direction and the thickness dimension t2 of the cover body 1 does not satisfy the range of 0.1≤t1 / t2≤0.2, even if the width dimension W of the anti-top groove 15 along the first direction satisfies the range of 0.8mm≤W≤1.2mm, the defective ratios of the horizontality of the sink 141 with the liquid injection hole 11 and the verticality of the inner wall of the liquid injection hole 11 of this batch of products are both greater than 0.01%, which does not meet the optimal design requirements, but compared with Comparative Examples 1 and 2, the defective ratio is much lower than the defective ratio when the anti-top groove 15 is not set.

[0059] In comparative example 7, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.25 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.125. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 0.75 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0151%.

[0060] In Comparative Example 8, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.25 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.125. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 1.3 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0159%.

[0061] In comparative example 9, the depth dimension t1 of the anti-top groove 15 along the second direction is first set to 0.25 mm, and then the thickness dimension t2 of the cover body 1 is set to 2 mm. At this time, the ratio of the depth dimension t1 of the anti-top groove 15 along the second direction to the thickness dimension t2 of the cover body 1 is 0.125. Finally, the width dimension W of the anti-top groove 15 along the first direction is set to 1.4 mm. After experimental verification, the defective ratio of the horizontality of the sink 141 with the injection hole 11 and the verticality of the inner wall of the injection hole 11 of this batch of products is 0.0160%.

[0062] It can be seen from Comparative Examples 7 to 9 that when the width dimension W of the anti-top groove 15 along the first direction does not satisfy the range of 0.8mm≤W≤1.2mm, even if the depth dimension t1 of the anti-top groove 15 along the second direction satisfies the range of 0.2mm≤t1≤0.4mm, and the ratio between the depth dimension t1 of the anti-top groove 15 along the second direction and the thickness dimension t2 of the cover body 1 satisfies the range of 0.1≤t1 / t2≤0.2, the defective ratios of the horizontality of the sink 141 with the liquid injection hole 11 and the verticality of the inner wall of the liquid injection hole 11 of this batch of products are both greater than 0.01%, which does not meet the optimal design requirements, but the defective ratio is much lower than that of Comparative Examples 1 and 2 when the anti-top groove 15 is not set.

[0063] Alternatively, as Figure 1 、 Figure 2As shown, the height dimension t3 of the boss 142 protruding from the second surface 13 along the second direction satisfies 0.35≤t3 / t2≤0.6. By limiting the ratio between the height dimension t3 of the boss 142 protruding from the second surface 13 along the second direction and the thickness dimension t2 of the cover plate body 1 to satisfy 0.35≤t3 / t2≤0.6, the height of the boss 142 protruding from the second surface 13 is determined based on the thickness of the cover plate body 1. This avoids, on the one hand, a situation in which the effective mating length between the inner wall of the injection hole 11 and the sealing pin is shortened due to the boss 142 protruding from the second surface 13 being too small, and, on the other hand, avoids a situation in which the boss 142 protruding from the second surface 13 is too large, resulting in the boss 142 occupying a larger space, thereby limiting the volume of the electrode group 200 and reducing the energy density.

[0064] Specifically, if Figure 1 、 Figure 2 As shown, the height dimension t3 of the boss 142 protruding from the second surface 13 along the second direction satisfies 0.7 mm ≤ t3 ≤ 1.2 mm. In this embodiment, the height dimension t3 of the boss 142 protruding from the second surface 13 along the second direction can be any value between 0.7 mm and 1.2 mm, or a range between any two values, such as 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, etc.

[0065] Alternatively, as Figure 1 、 Figure 2 As shown, the depth dimension of the recessed platform 141 is t4, and satisfies (t2-t1-t4) ≥ 0.3 mm. By limiting the difference between the thickness dimension t2 of the cover body 1, the depth dimension t1 of the top groove 15 along the second direction, and the depth dimension t4 of the recessed platform 141, so that the difference satisfies (t2-t1-t4) ≥ 0.3 mm, the remaining area of the cover body 1 after the recessed platform 141 and the top groove 15 are provided has sufficient material thickness to ensure sufficient structural strength.

[0066] Optionally, the width dimension of the projection area of the anti-top groove 15 along the second direction on the sinking platform 141 along the first direction is L, and satisfies L / W ≥ 0.6. By limiting the ratio between the width dimension L of the projection area of the anti-top groove 15 along the second direction on the sinking platform 141 along the first direction and the width dimension W of the anti-top groove 15 along the first direction, so that both satisfy L / W ≥ 0.6, it is ensured that when supporting the sinking platform 141, there is sufficient support area between the tooling for anti-top support and the sinking platform 141, thereby ensuring that the tooling for anti-top support has sufficient support strength for the sinking platform 141 to resist the force during punching.

[0067] Alternatively, as Figure 1 、 Figure 2As shown, the injection hole 11 includes a fixing hole section 111 and a guide hole section 112. The guide hole section 112 is located on the side of the injection hole 11 close to the first surface 12, and the fixing hole section 111 is located on the side of the injection hole 11 close to the second surface 13. The guide hole section 112 is trumpet-shaped, with the inner diameter gradually increasing as it moves away from the fixing hole section 111. The inner wall of the fixing hole section 111 is perpendicular to the first surface 12. The trumpet-shaped guide hole section 112 is provided on the injection hole 11 to guide the sealing pin into the injection hole 11. The fixing hole section 111 is provided with an inner wall perpendicular to the first surface 12, thereby ensuring that the inner wall of the fixing hole section 111 covers the outside of the sealing pin, thereby generating greater frictional resistance to the sealing pin and preventing it from falling off.

[0068] Alternatively, as Figure 1 、 Figure 2 As shown, the boss 142 is tapered with its outer diameter gradually decreasing as it approaches the pole group 200. By setting the boss 142 as a tapered shape with its outer diameter gradually decreasing as it approaches the pole group 200, it is convenient to use the tapered surface to guide the tooling for the reverse top support to be inserted into the reverse top groove 15.

[0069] In this embodiment, if Figure 3 As shown, a battery is also provided, comprising a battery housing 100, an electrode group 200, and the aforementioned battery cover. The battery housing 100 is a hollow shell structure with an opening. The battery cover is disposed over the opening of the battery housing 100 and seals the battery housing 100 to form a receiving cavity for accommodating the electrode group 200. By using the aforementioned battery cover, the battery improves sealing, reduces the probability of electrolyte leakage, and improves product quality. It also avoids the problem of sealing pins falling off during manufacturing, thereby improving the manufacturing yield rate.

[0070] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A battery cover, comprising a cover body with a liquid injection hole, characterized in that: The cover body includes a first surface, a second surface, a liquid injection structure, and an inverted top groove. The liquid injection structure is recessed from the first surface to the second surface, and is used to form a sunken platform on the first surface and a convex platform protruding from the second surface on the second surface. The liquid injection hole is located in the sunken platform. The inverted top groove is provided on the second surface and is arranged around the outer side of the convex platform. The width of the anti-top groove along the first direction is W, and satisfies 0.8mm≤W≤1.2mm; The depth dimension of the anti-top groove along the second direction is t1, and satisfies 0.2mm≤t1≤0.4mm; The thickness of the cover plate body is t2, and satisfies 0.1≤t1 / t2≤0.2; The height dimension of the boss protruding from the second surface along the second direction is t3, and satisfies 0.35≤t3 / t2≤0.6; A height dimension t3 of the boss protruding from the second surface along the second direction satisfies 0.7 mm ≤ t3 ≤ 1.2 mm; The depth dimension of the sink is t4, and satisfies (t2-t1-t4)≥0.3mm; The projection area of the anti-top groove on the sinking platform along the second direction has a width L along the first direction, and satisfies L / W ≥ 0.6; The injection hole includes a fixed hole section and a guide hole section, wherein the guide hole section is located on a side of the injection hole close to the first surface, and the fixed hole section is located on a side of the injection hole close to the second surface. The guide hole section is trumpet-shaped with an inner diameter gradually increasing away from the fixed hole section, and an inner wall of the fixed hole section is perpendicular to the first surface. The boss is in a conical shape with an outer diameter gradually decreasing in a direction approaching the pole group.

2. A battery, characterized in that The battery includes a battery casing, an electrode group and a battery cover as described in claim 1. The battery casing is a hollow shell structure with an opening. The battery cover is arranged on the opening of the battery casing and closes the battery casing to form a accommodating cavity for accommodating the electrode group.

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